Liquid volumetric test measurement apparatus include field test measure apparatus (commonly called a “prover”) that can be used to test the accuracy of the volumetric meter for a pump dispenser of a liquid. For example a prover can be used to test the accuracy of, and calibrate, the meter for a gasoline or diesel fuel pump dispenser at a gas station (gas bar). The prover is a precisely constructed vessel for holding an amount of the liquid that is pumped into the prover and includes an integrated gauge for precisely measuring the amount of liquid pumped into the prover through the dispenser's nozzle. Typically meter calibration for a gasoline or diesel fuel pump dispenser at a gas station may be accomplished by pumping a selected volume of the gasoline or diesel fuel into the prover that is indicated by a reading on the dispenser, for example 5.0 gallons. The dispenser's meter reading is then compared with the reading on the prover's integrated gauge to determine the precise amount of the fuel pumped into the prover, for example 4.75 gallons. In this the example the dispenser's meter delivery needs to be adjusted upwards since the dispenser's meter delivery is reading 0.25 gallons less than the actual volume as determined by the prover's gauge. The accumulated 4.75 gallons of fuel in the prover is poured out of the prover, and the prover is refilled again from the pump dispenser after the upwards adjustment of the pump dispenser's meter delivery. There is a standard procedure for pouring the accumulated fuel out of the prover since some fuel will remain in the prover due to adhesion of the fuel to the interior walls and bottom of the prover; that is, with each “emptying” of the prover, the goal is to keep precisely the same quantity of residue fuel by adhesion in the prover so that subsequent accuracy test volumes of the fuel pumped into the prover are not affected by deviations in the retained adhesion fuel in the prover from the previous emptying pour from the prover.
One example of a field test measure apparatus 100 (also referred to as a “prover” or simply “test measure”) that is used for calibration of gasoline or diesel fuel dispensers at gasoline stations is SERAPHIN® brand “Series E” test measure, which is illustrated in FIG. 1 and is available from Pemberton Fabricators, Inc., Rancocas, N.J., USA. Typical capacities of this type of handheld provers are from 1 U.S. gallon (5 liters) to 10 U.S. gallons (40 liters) of gasoline or diesel fuel. These provers are designed for top fill from a dispenser's nozzle 90 (partially shown in FIG. 1 in dashed lines) and top manual pour (emptying) from the prover. The prover is constructed from a material that does not react with the liquid being measured, and its interior volume is precisely calibrated to an integral gauge. For example if the liquid is a gasoline or diesel fuel, a stainless steel composition can be a selected material for fabrication of the prover. A handheld prover typically includes a rotatably-fastened handle 102; a neck section 104; a rolled bead top opening 104a at the liquid entry and exit end of the neck section; an integral gauge assembly 106 mounted on the neck section with a volumetric gauge in communication with the liquid level inside the neck section; a top cone section 108 having a pitch angle α; a cylindrical liquid containment section 110; and an interior bottom 112 (shown in dashed lines) that may be concave in shape.
As mentioned above the manual pour of liquid from the prover is controlled so that the volume of adhesion liquid left in the prover after repeated emptying of the prover remains consistently the same. For example in the United States, the national standard for pour control is currently contained in National Institute of Standards and Technology (NIST) Handbook 105-3 (2010) entitled “Specifications and Tolerances for Graduated Neck Type Volumetric Field Standards.” According to this NIST Handbook, handheld test measure apparatus require a 30 second (s) (±5 s) pour followed by a 10 s drain, with the apparatus held at a 10° to 15° angle from vertical during calibration and use. In Canada, the standard for pour control is currently contained in Measure Canada's “Guidelines for the Calibration and Certification of Volumetric Standards” (Issued October 2008; Revision Number: Rev. 1). The test measure apparatus is drained while tipping it upside down over a 30-second period. When the main flow ceases and the dribble of the liquid breaks into drops, the apparatus is turned completely upside down for a time period determined by the capacity of the test measure.
The volume of gasoline or diesel fuel (product) pumped into the prover from the pump dispenser is typically poured back into an underground storage tank (UST) 92 for the gasoline or diesel fuel via the UST fill tube 92a after removal of the UST fill tube grade cover 92b and fill cap 92c as illustrated in FIG. 2(a) and FIG. 2(b). Although a standard procedure, as described above, is followed for the manual pour from the prover into the UST fill tube, ambient air that is not saturated with product vapors enters the test measure apparatus, which results in the vaporization of liquid product when the test measure apparatus is filled with the next delivery from the fuel dispenser.
It is one object of the present invention to provide vapor containment and retention apparatus and methods during the pour of a volatile liquid from a test measure apparatus.
It is another object of the present invention to provide vapor containment and retention apparatus and methods during the pour of a volatile liquid from a test measure apparatus to improve the accuracy and repeatability of the test process.
It is another object of the present invention to expeditiously create from the volatile liquid poured into the pour vapor-containment apparatus a vapor-saturated environment within the pour vapor-containment apparatus from a test measure apparatus and transfer the vapor-saturated environment to the interior of the test measure apparatus to reduce vaporization losses during repeated calibrated volumetric pours into the test measure apparatus.
It is another object of the present invention to reduce the vaporization of a volatile liquid in an existing test measure apparatus without changing the capacity of the existing test measure apparatus or the existing test measure apparatus integrated gauge assembly's graduated scale.
It is another object of the present invention to allow users of an existing test measure apparatus to empty the apparatus using existing pour and drain procedures with minimal modifications and with improved accuracy and repeatability of the test process.